Apparatus And Methods For Placing Leads Using Direct Visualization

ABSTRACT

An apparatus for imaging a body structure within a body cavity includes a catheter including proximal and distal ends, an imaging element on the distal end, and an extension extending distally from the distal end for contacting a surface of a body cavity into which the catheter is introduced. The extension has a length to maintain the optical imaging element away from the surface. Optionally, a transparent member, e.g., an expandable balloon, may be attached to the distal end of the tubular member and the extension to isolate the imaging element from contact with fluid within the body cavity. During use, the catheter is inserted into a chamber of a beating heart, and the extension and/or balloon is placed against the wall of the chamber. Sufficient force is applied to stabilize the imaging element relative to the wall while the heart is beating.

This application is a continuation-in-part of co-pending applicationSer. No. 11/379,562, filed Apr. 20, 2006, which is acontinuation-in-part of application Ser. No. 11/269,976, filed Nov. 8,2005, which is a continuation of application Ser. No. 10/447,526, filedMay 29, 2003, now U.S. Pat. No. 6,979,290, which claims benefit ofprovisional application Ser. No. 60/384,262, filed May 30, 2002. Thisapplication also claims benefit of provisional application Ser. No.60/708,747, filed Aug. 16, 2005. The disclosures of each of thesereferences is expressly incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates generally to apparatus and methods fordelivering leads into a patient's body, and, more particularly, toapparatus and methods for delivering leads within body lumens of a heartand/to epicardial locations under direct visualization.

BACKGROUND

Minimally invasive procedures have been implemented in a variety ofmedical settings, e.g., for vascular interventions, such as angioplasty,stenting, embolic protection, electrical heart stimulation, heartmapping and visualization, and the like. One such procedure involvesdelivering an electrical lead into a coronary vein of a patient's heartthat may be used to electrically stimulate the heart.

During such procedures, instruments, fluids, and/or medicaments may bedelivered within a patient's vasculature using visualization tools, suchas x-ray, fluoroscopy, ultrasound imaging, endoscopy, and the like. Inmany procedures, it may be desired to deliver instruments through opaquefluids, such as blood, or other materials. Endoscopes have beensuggested that include devices for displacing these materials from anoptical path, e.g., by introducing a clear fluid from the endoscope inan attempt to clear its field of view. Yet there are still improvementsthat may be made to such devices.

Accordingly, apparatus and methods for imaging within body lumens and/orfor delivering instruments and/or fluids into a patient's body would beuseful.

SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods fordelivering leads into a patient's body, and, more particularly, toapparatus and methods for securing leads relative to tissue structuresand/or body lumens or cavities, and for delivering leads within bodylumens of a heart and/to epicardial locations under directvisualization.

In accordance with one aspect of the present invention, a system isprovided for delivering a lead into a body cavity of a patient thatincludes an imaging device, an elongate rail, and a lead. The imagingdevice may include a proximal end, a distal end sized for introductioninto a body cavity. The elongate rail may include a proximal end, adistal end sized for introduction into a body cavity, and one or morefixation elements on the distal end for securing the distal end to adelivery location within a body cavity. The elongate rail may be sizedfor introduction through a lumen of the imaging device, e.g., aguidewire. Alternatively, the elongate rail may be sized to beintroduced around the imaging device, e.g., a sheath or other tubularmember.

In one embodiment, the lead may include a proximal end, a distal end,and a lumen extending therebetween for receiving the elongate railtherein, such that the lead may be advanced over the elongate rail. Inanother embodiment, the lead may include a proximal end, and a distalend sized for introduction through a lumen of the elongate rail. Thelead may include one or more electrodes on the distal end, e.g., forpacing or other electrical stimulation of the heart.

In accordance with another embodiment, a method is provided fordelivering a lead within a body cavity. A distal end of an imagingdevice may be placed against a wall of a tissue structure adjacent abody cavity, and manipulated relative to the wall of the tissuestructure to image and/or otherwise identify a target site. A distal endof an elongate rail may be delivered via the imaging device, e.g.,through or over the imaging device, to the target site, and securedrelative to the target site. For example, the distal end may include oneor more fixation elements for securing the distal end to tissue at thetarget site.

The imaging catheter may be removed, and then a lead may be advanced viathe elongate rail, e.g., over or through the elongate rail, to thetarget site, and secured relative to the target site. For example, thedistal end of the lead may include one or more fixation elements forsecuring the distal end to tissue at the target site. The elongate railmay remain or may then be removed. In an alternative embodiment, thelead may be secured to the elongate rail, thereby securing the leadrelative to the target site.

In accordance with still another embodiment, a method is provided fordelivering a lead within a body cavity. An imaging catheter may beintroduced through one or more body lumens, and used to identify adelivery location for a lead. A distal end of an elongate rail may beintroduced via the imaging catheter to the identified delivery location,and secured at the delivery location. A lead may be delivered via therail to the delivery location, and secured relative to the deliverylocation. For example, the delivery location may be a location in theright ventricular septum or at another location within a chamber of aheart.

In accordance with yet another embodiment, a method is provided fordelivering a medical device within a body cavity. An imaging device maybe introduced into a thoracic cavity adjacent a heart of a patient. Asurface of the heart may be imaged using the imaging catheter toidentify a delivery location for a lead. A distal end of an elongaterail may be introduced via the imaging catheter to the deliverylocation, and secured to the delivery location, e.g., to epicardialtissue of the heart. A lead may be delivered via the elongate rail tothe delivery location, secured relative to the delivery location.

Other objects and features of the present invention will become apparentfrom consideration of the following description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constitute a part of this specification and includeexemplary embodiments to the invention, which may be embodied in variousforms. It is to be understood that in some instances various aspects ofthe invention may be shown exaggerated or enlarged to facilitate anunderstanding of the invention.

FIG. 1A is a perspective view of a first preferred embodiment of anapparatus for cannulating a body lumen, in accordance with the presentinvention.

FIG. 1B is a cross-sectional detail of a distal end of the apparatus ofFIG. 1A, showing a guidewire inserted through the apparatus.

FIG. 1C is a cross-section of the apparatus of FIG. 1A, taken along line1C-1C.

FIG. 2A is a perspective view of an alternative embodiment of theapparatus of FIG. 1A, having two degrees of steering.

FIG. 2B is a cross-section of the apparatus of FIG. 2A, taken along line2B-2B.

FIG. 3A is a cross-sectional detail, showing an alternative embodimentof an apparatus for cannulating a body lumen including a balloon, inaccordance with the present invention.

FIGS. 3B and 3C are cross-sections of the apparatus of FIG. 3A, takenalong lines 3B-3B, and 3C-3C, respectively.

FIG. 4 is a cross-sectional detail, showing another alternativeembodiment of an apparatus for cannulating a body lumen including aballoon, in accordance with the present invention.

FIGS. 5A-5C are cross-sectional side views of an embodiment of amechanically expandable member that may be substituted for an inflatableballoon in an apparatus, in accordance with the present invention.

FIG. 6 is a cross-sectional side view of a distal end of anotherembodiment of an apparatus for cannulating a body lumen, in accordancewith the present invention.

FIG. 7A is a side view of a catheter that may be included in theapparatus of FIG. 6.

FIG. 7B is a side view detailing a set of light guides that may beincluded in the catheter of FIG. 7A.

FIGS. 8A-8C are cross-sections of the catheter of FIG. 7, taken alonglines 8A-8A, 8B-8B, and 8C-8C, respectively.

FIGS. 9A-9C are cross-sections of the light guides of FIG. 7B, takenalong lines 9A-9A, 9B-9B, and 9C-9C, respectively.

FIG. 10 is a perspective detail of the apparatus of FIGS. 6 and 7A, withthe balloon omitted for clarity.

FIGS. 11A and 11B are exploded and perspective views of a optical fiberbundle having a lens attached thereto.

FIGS. 12A-12D are cross-sectional views of a portion of a heart, showinga method for delivering a lead into a right ventricle of the heart.

FIGS. 13A-13D are top views of a heart, showing a method for securing anepicardial lead to a heart.

DETAILED DESCRIPTION

Turning to the drawings, FIGS. 1A-1C show a first preferred embodimentof an apparatus 10 for imaging a body lumen, e.g., for visualizing,accessing, and/or cannulating a body lumen or tissue structure from abody cavity (not shown). In an exemplary embodiment, as explainedfurther below, the apparatus 10 may be used for imaging a wall of aright atrium of a heart, e.g., for visualizing, accessing, and/orcannulating a coronary sinus ostium, although the apparatus 10 may beused for visualizing, accessing, and/or cannulating other body lumensand/or tissue structures as well. Generally, as shown in FIG. 1A, theapparatus 10 may include a catheter or other elongate member 12, aballoon or other expandable member 50 on a distal end 16 of the catheter12, and an imaging assembly 62 carried by the distal end 16 of thecatheter 12 for imaging through the balloon 50.

The catheter 12 generally is an elongate tubular body including aproximal end 14, a distal end 16 having a size and shape for insertioninto a patient's body, and a central longitudinal axis 18 extendingbetween the proximal and distal ends 14, 16. The catheter 12 may includeone or more lumens 20 also extending between the proximal and distalends 14, 16, e.g., a cannulation lumen 20 a, an inflation lumen 20 b,and one or more lumens 20 c, 20 d (best seen in FIG. 1C) for the imagingassembly 62.

The catheter 12 may be substantially flexible, semi-rigid, and/or rigidalong its length, and may be formed from a variety of materials,including plastic, metal, and/or composite materials, as is well knownto those skilled in the art. For example, the catheter 12 may besubstantially flexible at the distal end 16 to facilitate advancementthrough tortuous anatomy, and/or may be semi-rigid or rigid at theproximal end 14 to enhance pushability of the catheter 12 withoutsubstantial risk of buckling or kinking.

Preferably, the catheter 12 is steerable, i.e., the distal end 16 may becontrollably deflected transversely relative to the longitudinal axis18. In the embodiment shown in FIGS. 1A-1C, a single pullwire or othersteering element 22 may be provided, e.g., within one of the lumens 20,for steering the distal end 16 of the catheter 12 in one transverseplane (thereby providing one degree of freedom). Alternatively, inanother embodiment, such as that shown in FIGS. 2A and 2B, two pullwires22′ may be provided for steering the distal end 16′ of the catheter 12′in two orthogonal planes (thereby providing two degrees of freedom).

The pullwire(s) 22 may be a cable, wire, band, and the like that may beslidably disposed within a lumen, such as the inflation lumen 20 b shownin FIG. 1C. The pullwire(s) 22 may be attached or otherwise fixedrelative to the catheter 12 at a location adjacent the distal end 16,preferably offset radially outwardly from the central axis 18. Thus,when the pullwire 22 is pulled proximally, e.g., from the proximal end14 of the catheter 12, a bending force may be applied to the distal end16, causing the distal end 16 to bend transversely relative to thecentral axis 18.

The catheter 12 may also include a handle or other control mechanism 30coupled to or otherwise provided on the proximal end 14 of the catheter12. The handle 30 may include one or more steering controls 32 that maybe actuated to steer the distal end 16 of the catheter 12. For example,as shown in FIG. 1, a dial 32 may be provided that may be coupled to thepullwire 22. The dial 32 may be rotated to apply a proximal force on thepullwire 22, thereby bending the distal end 16 of the catheter 12. In afurther alternative, the steering control 32 may include a slidercoupled to a pullwire (not shown) such that translation of the slidertranslates the pullwire, causing deflection of the distal tip of thecatheter 12 as the pullwire is placed in tension or compression.Exemplary embodiments of steering controls are disclosed in applicationSer. No. 11/062,074, filed Feb. 17, 2005, the entire disclosure of whichis expressly incorporated by reference herein.

The handle 30 may also include ports and/or other connections forconnecting other components to the catheter 12. It will be appreciatedthat any known connectors may be provided for permanently or temporarilyconnecting components to the catheter 12. For example, a luer lockconnector may be used to connect tubing or other fluid-conveyingcomponents to the handle 30.

As shown in FIG. 1A, a syringe or other source of fluid 34, e.g.,including saline, carbon dioxide, nitrogen, or air, may be connected viatubing 36 to the inflation lumen 20 b (not shown, see FIG. 1C) forinflating the balloon 50. In addition or alternatively, a stop-cock orcheck valve (not shown) may be included in the path of the inflationlumen 20 b to selectively maintain balloon inflation. For example, aluer-activated check valve may be used, such that a luer-lock syringe 34may be engaged with the apparatus 10 to open the valve for ballooninflation or deflation. When the syringe 34 is removed, the check valvemay automatically close to maintain balloon inflation. The syringe 34may also provide a source of vacuum for deflating the balloon 50, as isknown in the art. Another source of fluid 38, e.g., saline, and/or atherapeutic or diagnostic agent, may be connected via tubing 40 to thecannulation lumen 20 a for delivering fluid beyond the distal end 16 ofthe catheter 12.

In addition, an access port 42 may also communicate with the cannulationlumen 20 a, e.g., including a hemostatic seal and the like (not shown),for delivering one or more instruments (such as guidewire 80, shown inFIG. 1B) through the cannulation lumen 20 a, as explained further below.Optionally, the handle 30 may include a shape, size, and/or contour (notshown) for facilitating manipulating the catheter 12 during use.

Returning to FIGS. 1A and 1B, a substantially transparent balloon 50 maybe provided on the distal end 16 of the tubular member 12. The balloon50 may be expandable from a contracted condition (not shown) to anenlarged condition when fluid is introduced into an interior 60 of theballoon 50. In the embodiment shown, a channel 52 may extend through theballoon 50 that communicates with a lumen 20 of the catheter 12, e.g.,the cannulation lumen 20 a. Preferably, the channel 52 extends throughthe balloon 50 concentrically with the central axis 18, as best seen inFIG. 1B.

In an exemplary embodiment, the balloon 50 may be formed fromsubstantially noncompliant material, e.g., polytetrafluoroethylene(PTFE), expanded polytetrafluoroethylene (EPTFE), fluorinatedethylenepropylene (FEP), polyethylene teraphathalate (PET), urethane,olefins, and polyethylene (PE), such that the balloon 50 may expand to apredetermined shape when fully inflated to the enlarged configuration.Preferably, in the enlarged configuration, the balloon 50 may have adistal surface 54 that is substantially flat or otherwise configured forcontacting a wall of a body cavity, such as the right atrium (notshown). Alternatively, as shown in FIGS. 19A and 19B, an apparatus 710may be provided that carries a balloon 750 having a frustoconical shapeand/or a convex distal surface 754.

The material may be sufficiently flexible and/or elastic such that thedistal surface 54 may conform substantially to the wall of the bodycavity. Preferably, the balloon 50 is also sufficiently noncompliant todisplace blood or other fluid from between the distal surface 54 and thewall of the body cavity to facilitate imaging the wall through theballoon 50, as explained further below. Alternatively, the balloon 50may be formed from compliant and/or elastomeric materials, such assilicone, latex, isoprene, and chronoprene.

In the exemplary embodiment shown in FIG. 1B, the balloon 50 may beformed from one or more panels that may be attached to one another,e.g., using an adhesive (such as an adhesive cured using ultraviolet(“UV”) light), sonic welding, and/or heating, after lapping or buttingadjacent panels together. Alternatively, the balloon 50 may be moldedaround or within a mold (not shown) having a desired shape for theballoon 50 in the enlarged condition.

The resulting balloon 50 may include a proximal end 56 that may beattached to an outer surface of the catheter 12, e.g., using anadhesive, heating, sonic welding, an interference fit, and/or an outersleeve. The channel 52 may be formed from the same material as the restof the balloon 50, and a proximal end 58 of the channel may be attachedto the distal end 16 of the catheter 12, e.g., within or concentric withthe cannulation lumen 20 a. Alternatively, the channel may be formedfrom a semi-rigid or rigid tubular member, as shown in FIGS. 6-10, anddescribed further below.

In another alternative, the channel 52 may be formed of one or morematerials to provide a stiffness transition or multiple transitions. Ina further alternative, the channel 52 may be flexible or semi-flexible,but also biased and/or constrained in on or more directions, e.g., toavoid or minimize deflection of the channel 52 into a position that mayobscure the field of view beyond the apparatus 10. In still anotheralternative, the channel 52 may be transparent or semi-transparent tolight in the spectra used for imaging, e.g., to facilitate visualizationof devices, instruments, agents, and/or fluids passing through thetubular member. Alternatively, the channel 52 may be replaced orreinforced with any suitable stiffening element such as a wire, spring,composite element, plastic element, and the like.

As best seen in FIG. 1B, the interior 60 of the balloon 50 may have agenerally annular shape that preferably communicates with the inflationlumen 20 b (not shown, see FIG. 1C) of the catheter 12. Substantiallytransparent inflation media, e.g., saline, carbon dioxide, nitrogen,air, and the like, may be introduced into the interior 60 of the balloon50 to expand the balloon 50 towards the enlarged condition shown inFIGS. 1A and 1B. As used herein, “transparent” refers to any materialand/or fluid that may permit sufficient light to pass therethrough inorder to identify or otherwise visualize objects through the materialand/or fluid. “Light” as used herein may refer to light radiation withinthe visible spectrum, but may also include other spectra, such asinfrared (“IR”) or ultraviolet (“UV”) light.

Alternatively, the balloon and/or channel may have differentconfigurations, such as that shown in FIGS. 3A-3C and 4. For example, asshown in FIGS. 3A-3C, an apparatus 110 is shown that includes a catheter112 that may include one or more lumens, e.g., lumens 120 c, 120 d forreceiving components of an imaging assembly 162 therethrough, similar tothe previous embodiment. Unlike the previous embodiment, a cannulationlumen 120 a extends along an outer surface of the catheter 112 thatextends between a proximal end (not shown) to a distal end 116 of thecatheter 112. The lumen 120 a may be a separate tubular member attachedto the catheter 112 or may be an integral part of the catheter 112,e.g., formed as a single extrusion.

A balloon 150 may be carried on the distal end 116 of the catheter 112that defines an interior 160 communicating with an inflation lumen (notshown) that extends to the proximal end of the catheter 112, similar tothe previous embodiment. A channel 152 may extend along a wall of theballoon 150 that communicates with the cannulation lumen 120 a. Thechannel 152 may be defined by a panel of material attached to theballoon 150, similar to the materials and methods for making balloon 50,as described above. Alternatively, an inner balloon panel may beprovided within an outer balloon panel and the panels may be attached toone another, e.g., along one or more seams defining the channel 152.

A nipple or annular collar 157 may be provided on the distal surface 154of the balloon 150, e.g., to guide a guidewire 80 or other instrumentout of the balloon 150, and/or to stabilize the device relative to abody lumen or other tissue structure (not shown). Thus, a guidewire 80may be inserted into the cannulation lumen 120 a from the proximal endof the catheter 112, the channel 152 guiding the guidewire 80 throughthe balloon 150 until it exits through the nipple 157 to a locationbeyond the distal surface 152 of the balloon 150.

In another alternative, shown in FIG. 4, an inner balloon 251 may beprovided within an interior 260 of an outer balloon 250. The innerballoon 251 may be expandable to a size and/or shape that is smallerthan the outer balloon 250, thereby defining a channel 252 between theballoons 251, 252. Thus, a guidewire 80 or other instrument (not shown)may be inserted into a cannulation lumen 220 a, e.g., extending along anouter surface of the catheter 212. The guidewire 80 may enter thechannel 252 between the balloons 251, 252 until it exits through anipple 257, similar to the embodiment shown in FIGS. 3A-3C.

In yet another alternative, shown in FIGS. 5A-5C, an apparatus 310 maybe provided that includes a mechanically expandable member 350 carriedon a distal end 316 of a catheter 312. A frame 352 may be coupled to thedistal end 316 that may support a substantially transparent, flexiblemembrane 354. The frame 352 may include a plurality of members that aremovable away from and towards one another, thereby causing the membrane354 to move between contracted and enlarged conditions. Alternatively,the frame 352 may be constructed of plastic or wire mesh, or of a lasercut expandable framework.

The frame 352 may be actuated from a proximal end (not shown) of thecatheter 312, e.g., to cause the frame 352 to expand radially outwardly,as shown in FIGS. 5B and 5C. As the frame 352 expands, the membrane 354may provide a substantially transparent surface 356 through which anoptical imaging assembly, e.g., including an optical fiber bundle 364and/or a light guide 368, similar to that described further below, mayobtain optical images. Optionally, an interior 358 of the membrane 354may be filled with a substantially transparent fluid, similar to theballoons described above, to facilitate imaging through the expandablemember 350.

Returning to FIGS. 1A-1C, the imaging assembly 62 generally includes anoptical imaging element 64 that is exposed within the interior 60 of theballoon 50 for capturing light images through the balloon 50. In oneembodiment, the optical imaging element comprises an image sensor suchas a CCD, CMOS, and the like disposed distally, e.g., adjacent or withinthe distal end 16. In another embodiment, the optical imaging element 64may include a bundle of optical fibers, e.g. a coherent image bundle,that extends between the proximal and distal ends 14, 16 of the catheter12, e.g., through the lumen 20 d, as shown in FIG. 1C. The fiber bundle64 may include about ten thousand (10,000) optical fibers, although itmay include between about one and fifty thousand (1,000-50,000) fibersin order to provide a desired resolution in the images obtained by thefiber bundle 64.

A lens 66, e.g., a GRIN or self-oc lens, may be coupled to the fiberbundle 64 in order to focus light from beyond the distal surface 54 ofthe balloon 50 onto the fiber bundle 64 in order to generate a resolvedimage at the proximal end of the fiber bundle 64, as is well known tothose skilled in the art. Optionally, a directional prism or otheroptical element (not shown) may be provided for directing a field ofview of the fiber bundle 64 as desired, as explained further below. Inorder to decrease the tendency of bubbles to adhere to the distalsurface of a distal lens or other optical element (not shown), the lensmay be coated with a hydrophilic coating, or designed such that itsgeometry or the surrounding catheter geometry decreases the tendency ofbubbles to adhere, e.g., by providing a convex exposed surface. Otherfeatures, such as directed flushing, may be employed to dislodge anyadhered bubbles during use.

In addition, the imaging assembly 62 may include one or more lightsources disposed at the distal end 16 of the catheter 12. For example,the light sources may be one or more light emitting diodes.Alternatively, the imaging assembly 62 may include one or more lightguides 68 carried by the distal end 16 of the catheter 12 for deliveringlight into the interior 60 and/or through the distal surface 54 of theballoon 50. Although a single light guide 68 is shown in FIGS. 1B and1C, it will be appreciated that a plurality of light guides (not shown)may be provided in a common lumen or separate lumens (also not shown)within the catheter 12. The light guide(s) 68 may include a plurality ofoptical fibers, e.g., formed from acrylic and the like, that may extendto the proximal end 14 of the catheter 12. As shown in FIG. 1A, a sourceof light 70 may be coupled to the light guide(s) 68, e.g., via thehandle 30, for delivering light through the light guide(s) 68 and intothe balloon 50.

A device 72 may be coupled or otherwise provided at the proximal end 14of the apparatus 10 for acquiring and/or capturing images obtained bythe optical imaging assembly 62. For example, one or more lenses (notshown) may be coupled to the fiber bundle 64 for focusing and/orresolving light passing through the fiber bundle 64, e.g., to pass theimage to the device 72. The device 72 may include a CCD, CMOS, and/orother device, known to those skilled in the art, e.g., to digitize orotherwise convent the light images from the fiber bundle 64 intoelectrical signals that may be transferred to a processor and/or display(not shown).

For example, a computer (not shown) may be coupled to the device 72 (,see FIG. 1A), e.g., by a cable (not shown). Alternatively, instead ofthe computer, other display or capture devices may be coupled to thedevice 72, such as a laptop computer, handheld or PDA device, a computerterminal, a LCD display, standard video monitor, and the like (notshown), to display and/or store the images acquired from the fiberbundle 64. Optionally, the computer (or other capture device) mayprovide electrical power to the device 72, light source 70, and/or othercomponents of the apparatus 10.

For a cable connection between the device 72 and the computer, variousprotocols may be used, such as USB, Firewire, standard video signalprotocols, and the like. Alternatively, the computer may be coupled tothe device 72 via a wireless connection, for example, including one ormore transmitters and/or receiving using radio frequency signals,Bluetooth, infrared links, and the like.

Optionally, the apparatus 10 may include additional data acquisitionfeatures, such as a microphone (not shown), e.g., allowing procedurenotes to be dictated during an imaging procedure or allowing theapparatus 10 and/or computer 10 to be controlled by voice commands. Inaddition or alternatively, drivers and/or software may be stored on amemory chip (not shown) in the apparatus 10 that may be uploaded to thecomputer when connected to the apparatus 10. When a complex interface isused to connect the apparatus 10 to the computer or other displaydevice, the apparatus 10 and/or the computer may be capable of disablingthe complex interface and enable simple video output.

Turning to FIGS. 6-10, another preferred embodiment of an apparatus 410is shown for visualizing and/or cannulating a body lumen. Similar to theprevious embodiments, the apparatus 410 generally includes a catheter412, a balloon 450 carried by the catheter 412, and an imaging assembly462 for imaging through the balloon 450.

Also, similar to the previous embodiments, the catheter 412 may be anelongate tubular body including a proximal end 414, a distal end 416,and a central longitudinal axis 418 extending therebetween. The catheter412 may be substantially flexible, semi-rigid, and/or rigid along itslength, and may be formed from a variety of materials, includingplastic, metal, and/or composite materials. The catheter 412 may have adiameter between about five and ten French (1.67-3.33 mm), andpreferably between about six and eight French (2.00-2.67 mm).

The catheter 412 may include one or more lumens 420 also extendingbetween the proximal and distal ends 414, 416, e.g., a cannulation lumen420 a, an inflation lumen 420 b, and one or more lumens 420 c-f for theimaging assembly 462 and/or one or more pullwires or other steeringelements 422. In addition, the catheter 412 may include a handle (notshown) and/or other components, e.g., sources of fluid, a light source,an image capture device, and the like (also not shown) on the proximalend 414, similar to the other embodiments described herein.

Preferably, the catheter 412 includes multiple extrusions that areattached to one another to provide a desired length. For example, thecatheter 412 may include a proximal portion 412 a having a firstcross-section, shown in FIGS. 8A and 8B, and a distal portion 412 bhaving a second cross-section, shown in FIG. 8C. The proximal portion412 a may have a length between about nine and thirty six inches (22-90cm), and preferably between about eighteen and twenty eight inches(45-70 cm).

The proximal portion 412 a preferably includes three lumens, acannulation lumen 420 a, an inflation lumen 420 b, and an accessorieslumen 420 c. The cannulation lumen 420 a may provide a path for aguidewire or other instrument, fluid, and the like to pass between theproximal and distal ends 414, 416 of the catheter 412. Optionally, atube 424, e.g., made from polyamide and the like, may be provided withinthe cannulation lumen 420 a, e.g., to reinforce the cannulation lumen420 a and/or catheter 412. The inflation lumen 420 b may communicatewith an interior 460 of the balloon 450, similar to the previousembodiments, for delivering substantially transparent inflation mediainto the balloon 450. The accessories lumen 420 c may carry a pluralityof components, e.g., an optical imaging (fiber optic) bundle 464,pull-wire 422, and/or a set of light guides 468, similar to the previousembodiments described above.

With reference to FIGS. 7A and 8C, the distal portion 412 b may have alength between about 25.4-101.6 millimeters (mm), and preferably betweenabout 50.8-76.2 millimeters (mm). The distal portion 412 b may besubstantially permanently attached to the proximal portion 412 a, e.g.,using a lap or butt joint, and/or an adhesive, interference fit,heating, and/or sonic welding. The distal portion 412 b may includecontinuations of the cannulation lumen 420 a and inflation lumen 420 bfrom the proximal portion 412 a. In addition, the distal portion 412 bmay include a light guide lumen 420 d, a fiber optic lumen 420 e, and apullwire lumen 420 f that may communicate with the accessories lumen 420c when the proximal and distal portions 412 a, 412 b are attached to oneanother.

Preferably, the fiber optic lumen 420 e is located as far away from thecannulation lumen 420 a as possible in order to maximize a field of viewof the fiber bundle 464 received therein. For example, as shown in FIG.8C, the distal portion 412 b may include a ridge 421 extending axiallyalong an outer surface of the distal portion 412 b, thereby maximizing adistance that the fiber optic lumen 420 e may be disposed away from thecannulation lumen 420 a. When the fiber bundle 464 is inserted into thecatheter 412, the fiber bundle 464 may be received in the fiber opticlumen 420 e in the distal portion 412 b, and in the accessories lumen420 c in the proximal portion 412 a. The fiber bundle 464 may be securedat one or more locations within the lumens 420 e, 420 c, e.g., using anadhesive and the like. Thus, the location of the fiber bundle 464 may befixed in the distal portion 412 b to stabilize its field of viewrelative to the catheter 412.

The pullwire lumen 420 f may also be located as far away from thecentral axis 418, e.g., due to another ridge extending the outersurface. This arrangement may maximize a bending force applied to thecatheter 412 when the pullwire 422 is pulled proximally.

Turning to FIGS. 7B and 9A-9C, the set of light guides 468 may bereceived in the accessories lumen 420 c in the proximal portion 412 aand in the light guide lumen 420 d in the distal portion 412 b. The setof light guides 468 may include between about one and twenty five, andpreferably between about four and ten, elongate light guides. Each ofthe light guides 468 may be formed from a substantially transparentacrylic fiber or other light transmitting material, e.g., having adiameter between about twenty five micrometers and one millimeter (25μm-1 mm), and preferable between about two hundred fifty and fivehundred micrometers (250-500 μm).

At the proximal end 414 of the catheter 412, the light guides 468 may besubstantially cylindrical, while towards the distal end 416 of thecatheter 412, the light guides 468 may be tapered and/or flattened. Forexample, the light guides 468 may taper within a few inches of theproximal end 414 of the catheter 412, preferably reducing an overallcross-section of the light guides 468 by as much as fifty percent (50%).The light guides 468 may be disposed loosely within the accessorieslumen 420 c of the proximal portion 412 a.

The enlarged size of the light guides 468 at the proximal end 414 of thecatheter 412 may facilitate connecting the light guides 468 to a lightsource (not shown), as will be appreciated by those skilled in the art.Optionally, exposed lengths (not shown) of the light guides 468 beyondthe proximal end 414 of the catheter 412 may be further enlarged tofacilitate such connections. For example, if the light guides 468 areacrylic fibers, heat may be applied, e.g., up to one hundred seventydegrees Fahrenheit (170° F.), to cause the light guides 468 to shorten.The acrylic material may increase in diameter as it shortens, therebyincreasing the diameter of the light guides 468 by as much as threetimes as they shorten. This may allow the light guides 468 to becolumnated and connected to a light source without requiring a lens (notshown).

As the light guides 468 transition from the proximal portion 412 a tothe distal portion 412 b, they may be linearly aligned and/or secured toeach other, e.g., using an epoxy or other adhesive, and/or by reflowingthe fiber material, such that surfaces of adjacent fibers are bonded atadjacent contact points. To align the light guides 468 in a desiredorientation within the distal portion 412 b, the light guides 468 may bereceived in an axial ridge or slot 423 within the distal portion 412 b,as shown in FIG. 8C.

The bonded array of light guides 468 may provide a hinge, i.e., biasingthe distal portion 412 b of the catheter 412 to bend in a predetermineddirection. Specifically, the light guides 468 may provide a higherbending moment along a bond axis “x” (shown in FIG. 9C), whileexhibiting a much lower bending moment along an axis orthogonal to thebond axis “x.” As the pullwire 422 is pulled proximally, the force maybe transferred to the distal portion 412 b of the catheter 412. Becauseof the asymmetric bending moments created by the light guides 468, thedistal portion 412 b of the catheter 412 may bend in one planeorthogonal to the bond axis “x,” i.e., towards the pullwire 422, whileresisting bending along the bond axis “x.” This may cause the catheter412 to curve from a location where the pullwire 422 transitions frombeing located at the center of the catheter 412 (e.g., as shown in FIG.8A) to a location on the distal end 416 where the pull wire 422 is fixed(e.g., as shown in FIG. 8C).

Turning to FIGS. 10-11B, a bundle 464 of optical fibers may be provided,similar to the embodiments described above. Preferably, a lens 466 iscoupled to the fiber bundle 464, e.g., a GRIN or self-oc lens, asdescribed above. For example, as shown in FIGS. 11A and 11B, a sleeve467, e.g., shrink wrap and the like, may be provided that may be securedaround the lens 466 and the optical imaging bundle 464. Optionally, afluid or other material (not shown) may be provided between the lens 466and the optical imaging bundle 464 to minimize losses and/or reflectionat the transition, as is known to those skilled in the art.

Turning to FIG. 10 with continued reference to FIG. 6, a tubularextension 430 may extend from the distal end 416 of the catheter 412.The tubular extension 430 may include a lumen 432 extending betweenproximal and distal ends 434, 436 of the tubular extension 430.Preferably, the tubular extension 430 has a substantially smallerdiameter or other cross-section than the distal end 416 of the catheter412.

The proximal end 434 of the tubular extension 430 may be attached to thedistal end 416 of the catheter 412 such that it is coextensive with thecannulation lumen 420 a. Thus, an instrument or fluid introduced throughthe cannulation lumen 420 a may pass freely through the lumen 432 of thetubular extension 430. In addition, attaching the tubular extension 430eccentrically to the catheter 412 opposite the optical imaging bundle464 may minimize the extent that the tubular extension 430 obstructs thefield of view of the optical imaging bundle 464.

In one embodiment, the proximal end 434 of the tubular extension 430 maybe at least partially received in the cannulation lumen 420 a or in arecess (not shown) concentric with the cannulation lumen 420 a.Alternatively, the proximal end 434 of the tubular extension 430 may bebutted against the distal end 416 of the catheter 412. In addition oralternatively, the tubular extension 4430 may be bonded to the catheter412, e.g., using an adhesive, heating, sonic welding, and the like.

The balloon 450 may include a proximal end 452 attached to the distalend 416 of the catheter 412 and a distal end 456 attached to the distalend of the tubular extension 430. The proximal end 452 of the balloon450 may be secured to the outer surface of the catheter 412, e.g., usingan adhesive, heating, an interference fit, an outer collar (not shown),and the like, similar to the other embodiments described herein.

Turning to FIGS. 12A-12D, an imaging apparatus 10, such as any of thosedescribed elsewhere herein, may be included in a system or kit, alongwith an elongate rail 80, and/or a lead 100. As shown, the elongate rail80 is a guidewire including a proximal end (not shown), a distal end 83,and one or more fixation elements 82 on the distal end 83. In theexemplary embodiment shown, the fixation element 82 is a helical screw,which may include a sharpened tip to facilitate penetration into tissue.As the guidewire 80 is rotated about its longitudinal axis, the helicalscrew 82 may be screwed into tissue. To remove the helical screw 82, theguidewire 80 may be rotated in the opposite direction.

In alternative embodiment, the fixation element 82 may include otherstructures, e.g., that actively secure the distal end 83, e.g.,adhesives, hooks, pinchers, barbs, and the like. If the guidewire 80 issecured within a body lumen, e.g., a pulmonary artery, coronary vein,and the like, the fixation element 82 may be an expandable device, e.g.,a balloon or mechanically expandable device that may frictionally orotherwise engage surrounding tissue to secure the distal end 83.

During use, the imaging apparatus 10 and rail 80 may be used to delivera pacing or other transvenous lead into a patient's body, e.g.,endoluminally to a target location within a body lumen or cavity, orsurgically into body cavities, such as the thoracic cavity forepicardial lead placement. FIGS. 12A-12D show an exemplary endocardialplacement. Initially, as shown in FIG. 12A, the imaging apparatus 10 maybe advanced through the patient's vasculature, from a percutaneous entrysite, e.g., at a subclavian or femoral vein, into the patient's heart.As shown, the distal end 16 of the imaging catheter 12 may be introducedthrough the right atrium 92 and into the right ventricle 98.

An imaging device, e.g., including expandable member 50 and one or morelenses or other imaging assemblies may be used to visualize the interiorof the right ventricle 98 to facilitate identifying a suitable deliverylocation 96. For example, with the expandable member 50 expanded, thedistal end 16 may be directed against a wall of the right ventricle 98,e.g., against the right ventricular septum, and manipulated to move theexpandable member 50 (and imaging assembly) along the wall to identify atarget delivery location 96.

Turning to FIG. 12B, once a target location 96 is identified, theelongate rail 80 is introduced via the imaging apparatus 10 to thetarget delivery location. As shown, the rail 80 is a guidewire that maybe through an instrument lumen (not shown) in the imaging apparatus 10,e.g., from the proximal end (not shown) to the distal end 16 until theguidewire 80 is disposed adjacent or beyond the expandable member 50 atthe delivery location 96. The fixation element 82 on a distal end 83 ofthe guidewire 80 may be used to secure the guidewire 80 to the rightventricle 98 at the target location 96.

In an alternative embodiment, the rail may include a sheath or othertubular member (not shown) that may be advanced through a lumen of theimaging apparatus 10 or may be advanced around the imaging apparatus 10.The tubular member may include one or more fixation elements on thedistal end, which may be used to secure the tubular member to the targetlocation 96.

Turning to FIG. 12C, the imaging apparatus 10 may then be removed,leaving the rail 80 secured within the right ventricle 98. For example,the expandable member 50 may be collapsed, and the imaging apparatus 10removed over (or through) the rail 80.

As shown in FIG. 12D, an electrical pacing lead 100 and/or otherinstrument may then be advanced through the heart via the rail 80 untilthe lead 100 is disposed within the right ventricle 98 at the deliverylocation 96. Because cardiac leads are extremely flexible or floppy, therelative strength and/or rigidity of the guidewire 80 may facilitateadvancing the lead 100 through larger vessels, where the lead 100 mayotherwise wander or bind up. The lead 100 may then be affixed to thedelivery location 96, by attaching the fixation element to the deliverylocation. As shown, the lead 100 include a lumen for receiving the rail80 therethrough, thereby allowing the lead to be advanced over the rail80. Alternatively, the lead 100 may be introduced through a lumen of therail, e.g., if the rail is a sheath or other tubular member (not shown).

The lead 100 may include a helical screw (not shown) or other fixationelement, similar to the rail 80 for securing the lead 100 relative tothe target location 96. In this embodiment, the rail 80 may be removed,either before or after securing the lead 100 to the target location 96.Alternatively, the rail 80 may remain secured at the target location 96.In this alternative, the lead 100 may include one or more connectorsthat may secure the lead 100 to the rail 80, thereby securing the leadrelative to the target location 96.

In the another embodiment shown in FIG. 13A-13D, an imaging apparatus10, such as those described elsewhere herein, may be advanced into abody cavity, e.g., into a thoracic cavity. For example, the heart may beexposed using a sternotomy or a minimally invasive approach, e.g.,involving one or more ports (not shown) may be used to access thethoracic cavity and/or pericardial sac of the heart.

As shown in FIG. 13A, a distal end 16 of the imaging catheter 12 may bedisposed adjacent the patient's heart. The imaging apparatus 10 ismaneuvered through the pericardial space (not shown) until theexpandable member 50 is placed against the epicardium of the heart. Theexpandable member 50 may be expanded, and the epicardium imaged toidentify a target delivery location 96, e.g., above the right ventricle98. An imaging assembly (not shown) in the expandable member 50 may beused to directly visualize the exterior of the right ventricle 98, whichmay facilitate identifying a suitable delivery location 96.

Turning to FIG. 13B, an elongate rail 80 may be advanced through a lumen(not shown) in the imaging apparatus 10, e.g., from a proximal end (notshown) to the distal end 16, until the rail 80 is disposed beyond theexpandable member 50 at the delivery location 96. A fixation element 82on a distal end 83 of the guidewire 80 may be used to secure theguidewire 80 to the epicardium of the heart at the target location 96.As shown, the fixation element 82 is a helical screw, similar to theprevious embodiment.

Turning to FIG. 13C, the imaging apparatus 10 may then be removed,leaving the rail 80 secured to the target location 96. As seen in FIG.13D, an electrical pacing lead 100 and/or other instrument may then beadvanced through the pericardial space along the rail 80 until the lead100 is disposed adjacent the delivery location 96. Because cardiac leadsare extremely flexible or floppy, the relative strength and/or rigidityof the rail 80 may facilitate advancing the lead through the pericardialspace, where the lead 100 may otherwise wander or bind up. The lead 100may then be affixed to the delivery location 96, by attaching a fixationelement (not shown) on the lead 100 to the delivery location 96. Theguidewire 80 may then be removed. Alternatively, the guidewire 80 mayremain secured at the delivery location 96.

Alternatively and/or in addition, the apparatus previously describedherein may also incorporate deflectability, steerability, and/or apre-shaped element or a combination of these features in order toachieve further improved navigability.

Although different embodiments have been described herein withparticularity as including specific components and/or features, it willbe appreciated that each of the embodiments described above may includecomponents and/or features specifically described with respect toindividual embodiments. For example, any of the embodiments describedabove may include one or more of the following: a handle on a proximalend of a catheter, one or more pullwires or other steering elements forsteering a catheter and/or a localization/stabilization member, steeringcontrols or actuator, a source of light, a capture device, e.g.,including a display, processor for analyzing image data, and/or memoryfor storing imaging data, sources of fluid, e.g., for deliveringinflation media, diagnostic, and/or therapeutic agents, and the like.Thus, different components may be provided on each of the embodiments,depending upon a specific application.

In addition, each of the apparatus described may be used to perform anyof the procedures described herein and should not limited to thespecific examples described. For example, any of the apparatus describedmay be used for imaging, accessing, and/or cannulating a collapsiblelumen, such as the colon. Embodiments with channels through balloons orother expandable and/or displacement members may be used to deliverinsufflation media, e.g., carbon dioxide, nitrogen, and/or air, into acollapsible lumen to facilitate performing a procedure therein.

While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and described herein in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but, to the contrary, the invention is to coverall modifications, equivalents and alternatives falling within the scopeof the appended claims.

We claim:
 1. A method for delivering a lead within a body cavity, comprising: placing a distal end of an imaging device against a wall of a tissue structure adjacent a body cavity; manipulating the distal end relative to the wall of the tissue structure to identify a target site; delivering a distal end of an elongate rail via the imaging device to the target site; securing the distal end of the elongate rail to the target site; removing the imaging catheter; advancing a lead via the elongate rail to the target site; and securing the lead relative to the target site.
 2. The method of claim 1, wherein the body cavity comprises a right ventricle of a heart, and the target site comprises a location on the right ventricular septum.
 3. The method of claim 1, wherein the body cavity comprises a pericardial cavity of a heart, and the target site comprises a location on the epicardium of the heart.
 4. The method of claim 1, wherein the elongate rail comprises a guidewire.
 5. The method of claim 1, wherein the distal end of the elongate rail is delivered through a lumen of the imaging device.
 6. The method of claim 5, wherein the lead is advanced over the elongate rail.
 7. The method of claim 1, wherein the elongate rail comprises a fixation element on the distal end for securing the distal end of the elongate rail to the target site.
 8. The method of claim 7, wherein the active fixation element comprises at least one of a helical screw, an adhesive, a hook, a pincher, and a barb.
 9. The method of claim 1, wherein the imaging device is removed after securing the distal end of the elongate rail to the target site.
 10. The method of claim 1, wherein the imaging device is removed before advancing the lead via the elongate rail.
 11. The method of claim 1, further comprising removing the elongate rail from the body cavity after securing the lead relative to the target site.
 12. The method of claim 1, wherein the elongate rail remains secured to the target site after securing the lead relative to the target site.
 13. The method of claim 1, wherein the lead is secured to the distal end of the elongate rail, thereby securing the lead relative to the target site.
 14. The method of claim 1, wherein the elongate rail comprises a tubular member, and wherein delivering a distal end of the elongate rail via the imaging device comprises advancing a distal end of the tubular member over the imaging device.
 15. The method of claim 14, wherein the lead is advanced through the tubular member to the target site.
 16. A method for delivering a lead within a body cavity, comprising: introducing an imaging catheter through one or more body lumens; using the imaging catheter to identify a delivery location for a lead; introducing a distal end of an elongate rail via the imaging catheter to the identified delivery location; securing the distal end of the rail at the delivery location; delivering a lead via the rail to the delivery location; and securing the lead relative to the delivery location.
 17. The method of claim 16, wherein the delivery location comprises a location within a chamber of a heart.
 18. The method of claim 17, wherein the delivery location comprises a location on the right ventricular septum.
 19. The method of claim 16, wherein the elongate locating member comprises at least one of a guidewire and a sheath.
 20. The method of claim 16, wherein the distal end of the elongate rail comprises a fixation element for securing the distal end at the delivery location. 